Re: [boost] Re: new compile-time dimensional analysis and unitlibrary

From: Matthias Schabel (boost_at_[hidden])
Date: 2003-12-16 13:03:48

> That seems pointless
>
> Ugly
>
> Ugly
>
> Unhelpful

You're long on fruitless criticism and notably short on constructive  
comments and/or
suggestions.  I'm sure the group would be delighted to be enlightened  
by your brilliant
resolution of this conundrum.

> I have no problems with making degrees a unit.  Those shouldn't be
> mixed with anything else without conversions.  But radians are a
> different matter.  If I take arctan(1.0), I expect a number, not
> something with units.

That's purely by convention.  Trig functions use and return radians  
because that is the most
efficient way of implementing the underlying algorithms.  What do you  
expect the function
getSatelliteRollAngle() to return?  If it just returns a number,  
there's no way of knowing without
looking through the documentation, whereas a return type of radians (or  
degrees) is unambiguous
and forestalls potential programming errors.  This way the error will  
be caught at compile-time.
Do it your way and it may be caught when the Mars Lander impacts the  
surface at 6 km/s...

------------------------------------------------------------------------ 
---------------------------
Matthias Schabel, Ph.D.                           	
Utah Center for Advanced Imaging Research
729 Arapeen Drive
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801-706-5760 (cell)
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mschabel at ucair med utah edu